JP4755525B2 - Thermogravimetry equipment - Google Patents

Description

  The present invention relates to a thermogravimetric measuring apparatus that measures the weight of a workpiece to be processed with a measuring instrument and can quench the workpiece after heating.

  In order to determine the content of the heat treatment on the workpiece, the weight of the workpiece before and after the heat treatment is experimentally measured. In this experiment, a thermogravimetric apparatus is used. As the heat treatment for the object to be processed, there are processes such as carburizing, carbonitriding, and nitriding in which a chemically active reaction gas is introduced into a furnace to heat the object to be processed.

  When measuring the weight of an object to be processed during heat treatment in a reaction gas, if the measuring device is exposed to heat and reaction gas, failure or corrosion occurs.

  Therefore, there is a conventional thermogravimetric measuring apparatus that measures the weight of an airtight container into which a reaction gas is introduced while accommodating an object to be processed (see, for example, Patent Document 1). In this apparatus, the sealed container and the measuring device are isolated from each other by the sealed container itself, and the measuring device is not exposed to heat and reaction gas.

JP 59-54944 A

  However, in some cases, it is very convenient to measure the weight of the object to be processed and then quench it. However, in the conventional thermogravimetric measuring apparatus shown in Patent Document 1, the object to be processed is sealed in a sealed container. Since it is housed inside, there is a problem that the object to be treated after heating cannot be quenched.

  An object of the present invention is to provide a thermogravimetric measuring apparatus capable of quenching a workpiece after directly measuring the weight of the workpiece to be heated.

  The heat treatment furnace apparatus of the present invention includes a measuring instrument, a measuring instrument chamber, a charging chamber, a processing chamber, a heating chamber, and a take-out chamber. The measuring instrument has a main body, a measurement wire hanging from the main body, an upper end rotatably attached to the lower end of the measurement wire and a hook provided with a hook at the lower end, and an upper end locked to the hook. A mounting wire on which the workpiece is mounted at the lower end, and the weight of the workpiece acting on the measuring wire is measured. The measuring instrument chamber houses the measuring instrument, and the measuring wire penetrates the lower surface. The charging chamber is located below the measuring instrument chamber and includes an open / close door and an operation member. The measuring wire penetrates the upper surface, the mounting wire penetrates the lower surface, and the hook is in a non-contact state inside. To position. In the processing chamber, the mounting wire passes through the upper end communicating with the inside of the charging chamber from the lower surface of the charging chamber, and the object to be processed is positioned in a non-contact state at an intermediate portion inside. The heating chamber houses a heater that faces an intermediate portion of the outer peripheral portion of the processing chamber. The extraction chamber communicates with the lower end of the processing chamber on the upper surface, and stores quenching oil therein. The operating member swings the hook during operation to release the locking of the upper end portion of the mounting wire at the hooking portion.

In this configuration, when the operation member is operated after the workpiece stored in the processing chamber is heated by the heater, the hook swings and the upper end of the mounting wire at the latching portion is released. The mounting wire falls downward together with the object to be processed. The lower end of the processing chamber in which the workpiece is stored communicates with the inside of the take-out chamber that stores the quenching oil. The object to be processed dropped from the middle part of the processing chamber is immersed in quenching oil and quenched.

  Further, the operation member can be brought into contact with the intermediate portion of the hook during operation.

In this configuration, when the operating member is operated, it comes into contact with the intermediate portion of the hook, the hook swings about the upper end portion as a fulcrum, and the locking of the upper end portion of the mounting wire at the latching portion is reliably released.

Furthermore, the take-out chamber may be provided with a buffer member at the bottom.

In this configuration, the object to be processed that has fallen into the take-out chamber collides with the buffer member. The impact due to the drop is absorbed by the buffer member, and the object to be processed is not damaged.

  According to the thermogravimetric measurement apparatus of the present invention, the workpiece stored in the processing chamber is heated by the heater and then the operating member is operated to swing the hook so that the mounting wire in the latching portion is The upper end is unlocked, the mounting wire is dropped together with the object to be processed, and the object to be processed can be surely quenched by the quenching oil stored in the take-out chamber.

  FIG. 1 is a schematic cross-sectional view showing a configuration of a thermogravimetric measurement apparatus 10 according to an embodiment of the present invention. The thermogravimetric measurement apparatus 10 includes a measuring instrument 1, a measuring instrument chamber 2, a charging chamber 3, a processing tube 4, a heating chamber 5, an extraction chamber 6, and a frame 7.

The measuring instrument chamber 2 is supported and fixed on the upper surface of the frame 7, and the take-out chamber 6 is fixed on the lower surface of the frame 7. The upper surface of the charging chamber 3 is fixed in an airtight manner to the lower surface of the measuring instrument chamber 2 inside the frame 7. The upper end of the processing tube 4 is fixed to the lower surface of the charging chamber 3 in an airtight state. The lower end of the processing tube 4 is fixed to the upper surface of the extraction chamber 6 in an airtight state. The heating chamber 5 is provided with a heater 8 on the inner peripheral surface of the heat insulating layer 5 </ b> A, and is fixed to the frame 7 at a position facing an intermediate portion of the peripheral surface of the processing tube 4.
The measuring chamber 2, the charging chamber 3, the processing tube 4, and the take-out chamber 6 are arranged in this order in the vertical direction by the frame 7.

  The thermogravimetric measurement apparatus 10 also includes an inert gas supply source 21 and a valve 22 which are gas introduction means for a measuring instrument chamber, a reaction gas supply source 31 and a valve 32 which are gas introduction means for a charging chamber, and a charging chamber. Vacuum pump 34 and valve 33 as exhaust means, reaction gas supply source 41 and valve 42 as gas introduction means for processing tube, vacuum pump 44 and valve 43 as exhaust means for processing tube, and inertness as gas introduction means for heating chamber A gas supply source 51 and a valve 52 are provided.

  The thermogravimetric measurement apparatus 10 further includes a first heat shield plate 9A and a second heat shield plate 9B.

  The measuring instrument 1 includes a main body 11, a measuring wire 12, a hook 13, and a mounting wire 14. The measurement wire 12 is suspended from the main body 11. The hook 13 is attached to the lower end of the measurement wire 12. An upper end of the mounting wire 14 is detachably locked to the hook 13, and the workpiece 20 is mounted on the lower end. In the main body 11, a device for measuring the weight of the workpiece 20 acting on the measurement wire 12 is accommodated.

  The measuring instrument chamber 2 has a water-cooled jacket structure, and houses the main body 11 of the measuring instrument 1 and the measuring wire 12 penetrates the lower surface. The inert gas supply source 21 introduces an inert gas into the measuring instrument chamber 2 via the valve 22.

  The charging chamber 3 includes an opening / closing door 3A, and the measuring wire 12 penetrates the upper surface thereof and stores the hook 13 in a non-contact state. With this structure, the workpiece 20 can be easily mounted. The reactive gas supply source 31 introduces a reactive gas into the charging chamber 3 via the valve 32. The vacuum pump 34 discharges the gas in the charging chamber 3 through the valve 33.

  The processing tube 4 corresponds to the processing chamber of the present invention. As an example, the processing tube 4 is a quartz tube or a heat-resistant steel tube whose upper and lower ends are open. The upper end of the processing tube 4 communicates with the charging chamber 3. The lower end of the processing tube 4 communicates with the take-out chamber 6. A mounting wire 14 is inserted into the processing tube 4 from the upper end, and the workpiece 20 is stored in a non-contact state in the intermediate portion. The processing chamber of the present invention is not limited to a tubular shape, and any shape can be used as long as the processing object 20 can be stored in a non-contact state.

The reactive gas supply source 41 introduces reactive gas into the processing tube 4 from the lower end of the processing tube 4 via the valve 42. The vacuum pump 44 discharges the gas in the processing tube 4 from the lower end of the processing tube 4 through the valve 43. The reaction gas introduced into the processing tube 4 by the reaction gas supply source 41 and the gas discharged from the processing tube 4 by the vacuum pump 44 pass through the inside of the extraction chamber 6.

  The heating chamber 5 has a heat insulating structure by the heat insulating layer 5 </ b> A, and houses the heater 8 facing the intermediate portion of the peripheral surface of the processing tube 4. The inert gas supply source 51 introduces an inert gas into the heating chamber 5 via the valve 52.

  As an example, the inert gas introduced by the inert gas supply source 21 and the inert gas supply source 51 is nitrogen gas. The reaction gas introduced by the reaction gas supply source 31 and the reaction gas supply source 41 is, for example, a hydrocarbon gas, RX gas, alcohol vapor, ammonia gas, or the like used for carburizing or nitriding the workpiece 20 or the like. Any combination of gases.

The extraction chamber 6 communicates with the lower end of the processing tube 4 on the upper surface, and stores quenching oil therein. A heat shield shutter 6 </ b> A is provided in the upper portion of the take-out chamber 6. The heat shield shutter 6A is movable between a position where the lower end of the processing tube 4 is closed and a position where it is opened (indicated by reference numeral 6a 'in FIG. 1).

  The measuring instrument chamber 2, the charging chamber 3, the processing tube 4 and the take-out chamber 6 are arranged in the vertical direction with the measuring wire 12 and the mounting wire 14 as the center. In a state where the object to be processed 20 is disposed in an intermediate portion in the processing tube 4, the measuring wire 12, the hook 13, the mounting wire 14 and the object to be processed 20 are the measuring instrument chamber 2, the charging chamber 3 and the processing tube. It does not touch any of 4.

  The first heat shield plate 9 </ b> A is disposed between the lower surface of the measuring instrument chamber 2 and the upper surface of the charging chamber 3. The second heat shield 9 </ b> B is disposed throughout the interior of the processing tube 4 in the range from the lower surface of the charging chamber 3 to the upper end of the heater 5. However, it is not always necessary to arrange the entire area, and it is sufficient that the element is disposed at least part of the range. The processing tube 4 penetrates the heat insulating layer 5A in the heating chamber 5, and a second heat shield plate is provided at least in a portion of the heating chamber 5 where the processing tube 4 penetrates the upper heat insulating layer 5A. 9B may be arranged.

  These shielding plates are appropriately selected from materials such as a stainless steel plate, a heat-resistant steel plate, and an Inconel plate depending on the temperature conditions at the place of use.

  The inert gas supply source 21 communicates with the inside of the measuring instrument chamber 1 through a valve 22. The reactive gas supply source 31 communicates with the inside of the charging chamber 3 through a valve 32. The vacuum pump 34 communicates with the inside of the charging chamber 3 through the valve 33. The reactive gas supply source 41 communicates with the inside of the processing tube 4 through the valve 42 and the extraction chamber 6. The vacuum pump 44 communicates with the inside of the processing tube 4 through the valve 43 and the extraction chamber 6. The inert gas supply source 51 communicates with a space between the heater 8 in the heating chamber 5 and the processing tube 4 through a valve 52.

  2 and 3 are diagrams showing an example of the usage state of the thermogravimetric measurement apparatus 10 during the gas carburizing process. In the gas carburizing treatment, a gas obtained by adding a small amount of a hydrocarbon gas as an enriched gas to the RX gas as a carrier gas is used as a reaction gas. Since this process is performed at substantially atmospheric pressure, the vacuum pumps 34 and 44 are not used. An exhaust system duct (which always supplies negative pressure) replaces this.

In this process, nitrogen gas as an inert gas prevents the reaction gas from flowing into the measuring instrument chamber 2 and protects the workpiece 20 at the time of temperature rise, which is the first purpose of auxiliary cooling of the measuring instrument 1. And a third purpose for purging the reaction gas.

Nitrogen gas is supplied from the measuring instrument chamber 2, and reaction gas is supplied from the lower end of the processing tube 4. In order to achieve the second and third objects of the nitrogen gas, it is not necessary to supply the nitrogen gas from the measuring instrument chamber 2, and it can be separately supplied into the processing tube 4 from another position.

When nitrogen gas is allowed to flow into the processing tube 4, it is exhausted from below the processing tube 4. When the reaction gas flows into the processing tube 4, the reaction gas is exhausted from above the processing tube 4.

Specifically, first, the open / close door 3A of the charging chamber 3 is opened at normal temperature, the upper end of the mounting wire 14 with the workpiece 20 attached to the lower end is locked to the hook 13, and the open / close door 3A is closed. Next, as shown in FIG. 2, nitrogen gas is supplied from the inert gas supply source 21 to the measuring instrument chamber 2 through the valve 22, and the gas in the processing tube 4 is discharged through the valve 43. Further, nitrogen gas is introduced into the heating chamber 5 from the inert gas supply source 51 through the valve 52.

In this state, the heater 8 is turned on and the temperature inside the processing tube 4 is raised to 800 ° C. Thereafter, as shown in FIG. 3, RX gas is supplied from the reaction gas supply source 41 through the valve 42 into the processing tube 4 and the gas in the processing tube 4 is discharged through the valve 33.

In this state, the inside of the processing tube 4 is heated to 930 ° C. by the heater 8, and a hydrocarbon gas is added to the RX gas over a first predetermined time, and the inside of the processing tube 4 is passed from the reaction gas supply source 41 through the valve 42. (Carburization process). When the first predetermined time elapses, the addition of the hydrocarbon gas is stopped and held for the second predetermined time (diffusion process), and then the temperature is lowered to the quenching temperature of 850 ° C. and held for the third predetermined time. (Soaking process)

  When the third predetermined time has elapsed, the heat shield shutter 6A is opened and the workpiece 20 is dropped into the quenching oil in the extraction chamber 6 (quenching process). Here, the supply of RX gas is stopped, the heater 8 is turned off, and the inside of the processing tube 4 is exhausted through the valve 43. After a predetermined cooling time has elapsed, the workpiece 20 is taken out from the take-out chamber 6.

While the reactive gas supplied from the take-out chamber 6 is exhausted from the charging chamber 3 via the inside of the processing tube 4, the inert gas is introduced into the measuring instrument chamber 2, so that the reactive gas is measured by the measuring instrument. It does not flow into the chamber 2. The measuring instrument 1 accommodated in the measuring instrument chamber 2 is not corroded by being exposed to the reaction gas, and is not fouled by soot generated from the reaction gas. Further, the heat of the processing tube 4 heated by the heater 8 is shielded by the heat shield plates 9A and 9B, and is not conducted and radiated to the upper measuring instrument chamber 2. For this reason, the measuring instrument 1 accommodated in the measuring instrument chamber 2 is not exposed to high temperatures and fails.

  4-7 is a figure which shows an example of the use condition at the time of the vacuum carburizing process of the thermogravimetry apparatus 10. FIG. In the vacuum carburizing process, generally, only a hydrocarbon gas is used as a reaction gas, and RX gas as a carrier gas is not used. In this process, vacuum pumps 34 and 44 are used. In the second use state, the reaction gas is introduced into the processing tube 4 from the lower end.

In this process, the nitrogen gas as the inert gas prevents the reaction gas from flowing into the measuring device chamber 2 and is used for the first purpose of cooling the measuring device 1 as an auxiliary, second for rapidly cooling the workpiece 20. And a third object for restoring the pressure in the processing tube 4.

Nitrogen gas is supplied from the measuring instrument chamber 2, and reaction gas is supplied from the lower end of the processing tube 4. In order to achieve the second and third objects of the nitrogen gas, it is not necessary to supply the nitrogen gas from the measuring instrument chamber 2, and it can be separately supplied into the processing tube 4 from another position.

During the supply of the reaction gas, exhaust is performed from above the processing tube 4 and exhausted from below the processing tube 4 only during rapid cooling.

Specifically, first, the open / close door 3A of the charging chamber 3 is opened at normal temperature, the upper end of the mounting wire 14 with the workpiece 20 attached to the lower end is locked to the hook 13, and the open / close door 3A is closed. Next, as shown in FIG. 4, a small amount of nitrogen gas is supplied from the inert gas supply source 21 to the measuring instrument chamber 2 through the valve 22, while being exhausted by the vacuum pump 44 through the valve 43. The inside is reduced to a predetermined pressure. The supply of a small amount of nitrogen gas can be omitted. Further, nitrogen gas is introduced into the heating chamber 5 from the inert gas supply source 51 through the valve 52.

In this state, the heater 8 is turned on and the temperature inside the processing tube 4 is raised to 1000 ° C. Next, evacuation is performed by the vacuum pump through the valve 33, and the valve 43 is closed to switch the evacuation system. Thereafter, as shown in FIG. 5, the hydrocarbon gas is supplied from the reaction gas supply source 41 through the valve 42 into the processing tube 4 over the first predetermined time, and exhausted by the vacuum pump 34 through the valve 33. Then, the inside of the processing tube 4 is set to a second predetermined pressure (carburizing step). The hydrocarbon gas can be supplied continuously or intermittently.

When the first predetermined time has elapsed, the supply of hydrocarbon gas is stopped and held for a second predetermined time (diffusion process). When the second predetermined time has elapsed, the inside of the processing tube 4 is evacuated by the vacuum pump 44 via the valve 43, and the valve 33 is closed to switch the evacuation system. Next, the heater 8 is turned off, and as shown in FIG. 6, a large amount of nitrogen gas is supplied from the inert gas supply source 21 through the valve 22 to rapidly cool the workpiece 20 (gas cooling step).

  Further, as shown in FIG. 7, the supply amount of nitrogen gas from the inert gas supply source 21 is returned to the original state, the evacuation system is switched in the same manner as described above, and the vacuum pump 34 is connected via the valve 33. To exhaust the inside of the processing tube 4. Thereafter, the heater 8 is turned on again to raise the temperature in the processing tube 4 to a predetermined quenching temperature (850 degrees) and hold for a third predetermined time (a soaking step).

  When the third predetermined time has elapsed, the heat shield shutter 6A is opened, and the workpiece 20 is dropped into the quenching oil in the extraction chamber 6 (quenching process). Here, after the heater 8 is turned off and the temperature is sufficiently lowered, evacuation by the vacuum pump 34 is stopped, and after returning to atmospheric pressure, the supply of nitrogen gas from the inert gas supply source 21 is also stopped. After a predetermined cooling time has elapsed, the workpiece 20 is taken out from the take-out chamber 6.

While the reactive gas supplied from the take-out chamber 6 is exhausted from the charging chamber 3 via the inside of the processing tube 4, the inert gas is introduced into the measuring instrument chamber 2, so that the reactive gas is measured by the measuring instrument. It does not flow into the chamber 2. The measuring instrument 1 accommodated in the measuring instrument chamber 2 is not corroded by being exposed to the reaction gas, and is not fouled by soot generated from the reaction gas. Further, the heat of the processing tube 4 heated by the heater 8 is shielded by the heat shield plates 9A and 9B, and is not conducted and radiated to the upper measuring instrument chamber 2. For this reason, the measuring instrument 1 accommodated in the measuring instrument chamber 2 is not exposed to high temperatures and fails.

  In both of the gas carburizing process and the vacuum carburizing process, a measuring wire 12 suspended from the main body 11 of the measuring instrument 1 housed in the measuring instrument chamber 2 located at the uppermost part is connected via a hook 13 and a mounting wire 14. The carburizing process is performed on the workpiece 20 that is suspended. During the carburizing process, the measuring wire 12, the hook 13, the mounting wire 14, and the workpiece 20 do not touch any of the measuring instrument chamber 2, the charging chamber 3, and the processing tube 4. The measuring device 1 can accurately measure the change in the weight of the workpiece 20 acting on the measuring wire 12 from the start to the end of the carburizing process.

  Since an inert gas is introduced into the heating chamber 5 that houses the heater 8 facing the middle portion of the peripheral surface of the processing tube 4, even if the processing tube 4 is damaged, damage to the heater 8 is minimized. be able to. Moreover, the danger of the explosion by contact with the combustible gas introduce | transduced in the processing pipe | tube 4 and air can be avoided.

  In addition, the space between the measuring instrument chamber 2 and the charging chamber 3, the space between the charging chamber 3 and the processing tube 4, and the space between the processing tube 4 and the extraction chamber 6 are airtight. For this reason, reaction gas can be introduce | transduced in the process pipe | tube 4 and it can be set as a required atmosphere, and surface hardening heat processing, such as an atmospheric-pressure carburizing process and a vacuum carburizing process, can also be performed.

  FIG. 8 is a cross-sectional view showing an internal configuration of the charging chamber 3. Inside the insertion chamber 3, the lower end portion of the measuring wire 12 hanging from the main body 11 of the measuring instrument 1 is located. A hook 13 is swingably attached to a pin 15 attached to the charging chamber 3 at the lower end of the measurement wire 12. A notch 13 </ b> A is formed at the lower end of the hook 13. The upper end of the mounting wire 14 is hooked on the notch 13A.

  The insertion chamber 3 is provided with an operation member 3B. The operation member 3B is an air cylinder as an example, and the actuator 3C faces the intermediate portion of the hook 13 in the horizontal direction. When the operation member 3B is driven, the actuator 3C comes into contact with the intermediate portion of the hook 13 in the horizontal direction, and the hook 13 swings around the pin 15 as indicated by a two-dot chain line in FIG. As a result, the upper end of the mounting wire 14 is removed from the notch 13 </ b> A, and the mounting wire 14 falls downward together with the workpiece 20.

FIG. 9 is a cross-sectional view showing an internal configuration of the take-out chamber 6. The lower end of the processing tube 4 in which the workpiece 20 is accommodated communicates with the inside of the extraction chamber 6, and the extraction chamber 6 stores quenching oil 62 therein. When the upper end of the mounting wire 14 is removed from the notch 13 </ b> A, the workpiece 20 drops downward together with the mounting wire 14. The workpiece 20 is immersed in the quenching oil 62 in the take-out chamber 6 and rapidly cooled to be quenched.

  A buffer member 61 is disposed on the bottom surface inside the take-out chamber 6. The buffer member 61 absorbs an impact when the workpiece 20 is dropped, and prevents the workpiece 20 from being damaged. It also reduces the impact sound. As the buffer member 61, for example, a sponge sheet can be used.

  In the above configuration, the reaction gas supply source 31 and the valve 32, the vacuum pump 34 and the valve 33, the reaction gas supply source 41 and the valve 42, the vacuum pump 44 and the valve 43 are not necessarily essential. By providing the switching valve and the connecting pipe, the vacuum pump 34 and the vacuum pump 44 can be shared. The supply / exhaust position can also be changed within a range in which the same purpose can be achieved. Further, when it is not necessary to introduce an inert gas into the heating chamber 5, the nitrogen gas supply source 51 and the valve 52 can be omitted.

1 is a schematic cross-sectional view showing a configuration of a thermogravimetric measurement apparatus 10 according to an embodiment of the present invention. It is a figure which shows an example of the use condition at the time of the gas carburizing process of the thermogravimetry apparatus. It is a figure which shows the use condition at the time of the gas carburizing process. It is a figure which shows an example of the use condition at the time of the vacuum carburizing process of the thermogravimetry apparatus. It is a figure which shows the use condition at the time of the vacuum carburizing process. It is a figure which shows the use condition at the time of the vacuum carburizing process. It is a figure which shows the use condition at the time of the vacuum carburizing process. 3 is a cross-sectional view showing an internal configuration of a charging chamber 3. FIG. It is sectional drawing which shows the structure inside the extraction chamber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measuring device 2 Measuring device room 3 Loading chamber 3B Operation member 4 Processing pipe (processing chamber)
5 Heating chamber 6 Unloading chamber 10 Thermogravimetric measuring device 11 Main body 12 Measuring wire 13 Hook 13A Notch (holding part)
14 Wire for mounting

Claims (3)

A main body, a measurement wire hanging from the main body, an upper end rotatably attached to the lower end of the measurement wire and having a hook at the lower end, and an upper end locked to the hook at the lower end A measuring instrument for measuring the weight of the object to be processed acting on the measuring wire,
While storing the measuring instrument, a measuring instrument chamber through which the measuring wire penetrates the lower surface,
Located below the measuring instrument chamber and provided with an open / close door and an operating member, the measuring wire penetrates the upper surface, the mounting wire penetrates the lower surface, and the hook is located in a non-contact state inside. A charging room,
The mounting wire passes through the upper end communicating with the inside of the charging chamber from the lower surface of the charging chamber, and the processing chamber in which the object to be processed is positioned in a non-contact state in the inner middle portion;
A heating chamber that houses a heater facing an intermediate portion of the outer peripheral portion of the processing chamber;
A lower end of the processing chamber communicates with the upper surface, and an extraction chamber storing quenching oil therein,
The thermogravimetric measuring apparatus, wherein the operating member swings the hook during operation to release the locking of the upper end portion of the mounting wire at the hooking portion.   The thermogravimetric measurement apparatus according to claim 1, wherein the operation member abuts against an intermediate portion of the hook during operation.   The thermogravimetric measurement apparatus according to claim 1, wherein the take-out chamber includes a buffer member at a bottom portion.

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